The MovePhotoSet method moves a photoset from one group to another. This method can also be used to change the position of a photoset within the group.
void MovePhotoSet( long photoSetId, long destGroupId, int index )
The photoset identified by the photoSetId parameter and the group identified by the destGroupId parameter must be owned by the currently authenticated user.
To change the position of a photoset within the group, specify the identifier of the containing group in destGroupId. The index parameter is zero-based, that is, the very first item in the group has index 0, the following item has index 1, and so on.